A simple method for non-parametric estimation of the probability distribution function of diatomic molecules by electron diffraction

Treating the Debye intensity relationship as a linear Fredholm integral equation of the first kind, a method is developed for a non-parametric estimation of the probability distribution function P/r) for diatomic molecules from electron-diffraction data. Since the problem is an ill-posed one, Tikhonov's regularization procedure was used for the solution. The method was applied to iodine for which the non-parametric P/r) function is obtained. Based on this function the electron-diffraction parameters r_g, r_a and l_a are estimated by the linear least-squares method without a priori assumptions about the form of the vibrational potential. Approximating the potential by the Dunham expansion, the parameters r_e, ω_e, K₃ and K₄ are also estimated. The results are compared with those obtained from conventional analytical representation of an intensity function. Comparison is also made with spectroscopic data for iodine.     

Voltammetric determination of nitrate,perchlorate and iodide at a hanging electrolyte drop electrode

The use of a hanging electrolyte drop electrode is examined for the determination of nitrate, perchlorate and iodide. A three-electrode system was used with a polarographic analyzer. Crystal violet dicarbollylcobaltate(III) electrolyte in the nitrobenzene phase and magnesium sulphate in the aqueous phase with a Pb/PbSO₄ reference electrode made it possible to increase the viable potential range. For nitrate, the peak current/concentration relation was linear over the range 0–5 × 10^?5 M, and nitrate in potable water was easily determined.     

Sensitive spectrophotometric determination of palladium with tin(II) chlorided and rhodamine-6g after flotation

Palladium is determined by reaction with tin(II) chloride and rhordamine-6G in hydrochloric acid medium, flotation of the ion-association complex, [(R6G⁺)₂Pd (SnCl^?₃)₄]·[(R6G⁺) (SnCl^?₃] with di-isopropyl ether, and dissolution in acetone for spectrophotometry. The molar absorptivity is 2.84 x 10⁵ l mol^?1 cm^?1 at 530 nm; Beer's law is obeyed in the range 0.05–0.35 μg Pd ml^?1. Other platinum metals and silver interfere. Traces of palladium in silver metal are determined after extraction of palladium with dimethylglyoxime in chloroform.     

Spectrophotometry Determination of Copper and Palladium Using Some 1,3,5-Triphenylformazans

A new rapid and accurate method for the spectrophotometric microdetermination of Cu(II) and Pd(II) using some 1,3,5-triphenylformazans (I) is given. The optimum conditions for the formation of the complexes are extensively investigated. The ligands form 1:1 and 1:2 (M:L) complexes with Cu and Pd ions, Beer's law is obeyed up to 3.8 and 6.5 ppm Cu and Pd respectively. The influence of foreign ions is investigated. The ligands were used successfully as indicators in spectrophotometric titration of Cu and Pd ions with EDTA and CDTA.     

KX-ray production cross sections for heavy target elements and14N,40Ar projectiles above the coulomb barrier

KX-ray production cross sections have been measured for beams of¹⁴N at 92, 103, 115 and 180 MeV and⁴⁰Ar at 180 and 300 MeV on targets with atomic numbers ranging from 40 to 90. We find that the measured values can be well reproduced with a plane wave Born calculation, provided that corrections for the Coulomb deflection of the projectile, the increased binding energy of theK-shell electron and relativistic effects of theK-shell wave function are taken properly into account.     

A rapid means for the synthesis of aldehyde acetals

Conclusions A convenient rapid method has been proposed for the acetalization of aldehydes by ethyl orthoformate in the presence of trace amounts of perchloric acid.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 921–923, April, 1986.     

Determination of uranium in wet phosphoric acid by extraction with octylphenylphosphoric acid

A method for quantitative determination of uranium in phosphoric acid and wet phosphoric acid has been developed. After reduction with Fe, uranium(IV) is extracted with a kerosene solution of octylphenylphosphoric acid. The uranium was stripped with 10M H₃PO₄, containing H₂O₂, and then determined spectrophotometrically with Arsenazo III and by direct uranium(IV)-phosphoric acid solution measurements.     

Comparison of the acid strength of solid catalysts

The catalytic activity of some solid acidic catalysts was tested in the depolymerization of paraldehyde. It was found that the activities of sulfonated ion exchange resin and mounted phosphotungstic acid strongly exceed the activity of silica-alumina and other oxide catalysts. By means of Brönsted relationship, the differences in H_O of the surfaces were estimated.

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